Display unit, method of manufacturing the same, and electronic apparatus

ABSTRACT

A display unit includes: a display layer including a pixel electrode; a semiconductor layer provided in a layer below the display layer, the semiconductor layer including a wiring layer that includes a material removable by an etchant by which the pixel electrode is also removable; and a terminal section configured to electrically connect the semiconductor layer to an external circuit, the terminal section including a first electrically-conductive layer made of a material same as a material of the wiring layer.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/387,114, filed on Dec. 21, 2016, which application is acontinuation of U.S. patent application Ser. No. 14/884,474, filed onOct. 15, 2015, and issued as U.S. Pat. No. 9,548,346 on Jan. 17, 2017,which application is a continuation of U.S. patent application Ser. No.14/155,703, filed on Jan. 15, 2014, and issued as U.S. Pat. No.9,219,081 on Dec. 22, 2015, which application claims priority toJapanese Priority Patent Application JP 2013-013555 filed in the JapanPatent Office on Jan. 28, 2013, the entire content of which is herebyincorporated by reference.

BACKGROUND

The present application relates to a display unit having a semiconductorlayer provided, for example, with a thin film transistor (TFT), to amethod of manufacturing the same, and to an electronic apparatusincluding the display unit.

A display unit such as an organic electro luminescence (EL) display unitis a display device in which luminance is controlled by a currentflowing in an organic light-emitting diode. Therefore, in such a displayunit, there is a disadvantage that unevenness in characteristics of alow-temperature polysilicon TFT generally used as a switching element iseasily expressed as display unevenness.

To resolve the foregoing disadvantage, in an organic EL display unit ofrecent years, a method of resolving unevenness in characteristics of aTFT to improve display performance by devising a drive circuit has beenreported. In contrast, for reasons such as that, in the organic ELdisplay unit, for example, the number of TFTs used therein and thenumber of wiring circuits used therein are increased compared to in aliquid crystal display unit, the area of a capacitor is increased, andthereby, the circuit of the organic EL display unit is complicated.Therefore, in the organic EL display unit, there have been disadvantagesthat the layout space is tight, the number of short-circuit faults isincreased, and the yield is lowered.

A short-circuit fault is caused by incoming dust upon dry-etching awiring layer formed comparatively thick in order to decrease aresistance. Therefore, for example, as described in Japanese UnexaminedPatent Application Publication No. H09-127555, a method with the use ofwet etching has been disclosed as a processing technique of the wiringlayer.

SUMMARY

The wiring layer is also used as a terminal section for connection withan external circuit such as a flexible printed circuit, and is connectedto the external circuit through a mounted member. However, since thewiring layer is exposed as the uppermost surface of the terminal sectionuntil the mounted member is laminated, there has been a disadvantagethat the wiring layer is damaged in other wet etching step such as astep of processing a pixel electrode of a display element, leading tovariations in display performance.

It is desirable to provide a display unit, a method of manufacturing thesame, and an electronic apparatus that are capable of suppressingvariations in display performance.

According to an embodiment of the present application, there is provideda display unit including: a display layer including a pixel electrode; asemiconductor layer provided in a layer below the display layer, thesemiconductor layer including a wiring layer that includes a materialremovable by an etchant by which the pixel electrode is also removable;and a terminal section configured to electrically connect thesemiconductor layer to an external circuit, the terminal sectionincluding a first electrically-conductive layer made of a material sameas a material of the wiring layer.

According to an embodiment of the present application, there is provideda method of manufacturing a display unit, the method including: (A)forming a wiring layer in a semiconductor layer on a substrate, andforming a first electrically-conductive layer in a terminal section, thefirst electrically-conductive layer being made of a material same as amaterial of the wiring layer; (B) forming, as a continuous film, a pixelelectrode on the semiconductor layer and the firstelectrically-conducive layer, the pixel electrode configuring a displaylayer, and the pixel electrode being made of a material removable by anetchant by which the wiring layer is also removable; and (C) removingpart or all of the pixel electrode on the first electrically-conducivelayer to from the terminal section.

According to an embodiment of the present application, there is providedan electronic apparatus with a display unit, the display unit including:a display layer including a pixel electrode; a semiconductor layerprovided in a layer below the display layer, the semiconductor layerincluding a wiring layer that includes a material removable by anetchant by which the pixel electrode is also removable; and a terminalsection configured to electrically connect the semiconductor layer to anexternal circuit, the terminal section including a firstelectrically-conductive layer made of a material same as a material ofthe wiring layer.

In the display unit, the method of manufacturing the same, and theelectronic apparatus according to the above-described embodiments of thepresent application, the wiring layer and the pixel electrode are formedof the materials that are removable by the same etchant. The terminalsection includes the first electrically-conductive layer formed at leastin the same step as a step in which the wiring layer is formed. In thestep of forming the terminal section, the metal film to become the pixelelectrode is formed on the first electrically-conductive layer, andsubsequently, part or all of the metal film on the firstelectrically-conductive layer is removed. Thereby, damage due to etchingof the electrically-conductive layer configuring the terminal section isreduced.

According to the display unit, the method of manufacturing the same, andthe electronic apparatus according to the above-described embodiments ofthe present application, the electrically-conductive layer (the firstelectrically-conductive layer) configuring the terminal section isformed in the same step as of the step in which the wiring layer isformed, the metal film to become the pixel electrode of the displaylayer is formed on the electrically-conductive layer, and subsequently,part or all of the metal film is removed. Thereby, damage due to etchingof the terminal section is reduced, and variations in displayperformance are suppressed. Therefore, a highly-reliable electronicapparatus is provided.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, and are intended toprovide further explanation of the technology as claimed.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments and,together with the specification, serve to explain the principles of thetechnology.

FIG. 1 is a diagram illustrating a configuration of a display unit.

FIG. 2 is a diagram illustrating an example of a pixel drive circuitillustrated in FIG. 1.

FIG. 3A is a plan view illustrating a configuration of a display unitaccording to a first embodiment of a present disclosure.

FIG. 3B is a cross-sectional view of the display unit illustrated inFIG. 3A.

FIG. 4A is a cross-sectional view illustrating a method of manufacturingthe display unit illustrated in FIGS. 3A and 3B in order of steps.

FIG. 4B is a cross-sectional view illustrating a step following a stepof FIG. 4A.

FIG. 4C is a cross-sectional view illustrating a step following the stepof FIG. 4B.

FIG. 4D is a cross-sectional view illustrating a step following the stepof FIG. 4C.

FIG. 5A is a cross-sectional view illustrating a step following the stepof FIG. 4D.

FIG. 5B is a cross-sectional view illustrating a step following the stepof FIG. 5A.

FIG. 5C is a cross-sectional view illustrating a step following the stepof FIG. 5B.

FIG. 6 is a cross-sectional view illustrating a configuration of aterminal section of a display unit according to a second embodiment ofthe present disclosure.

FIG. 7A is a cross-sectional view illustrating a method of manufacturingthe display unit illustrated in FIG. 6 in order of steps.

FIG. 7B is a cross-sectional view illustrating a step following a stepof FIG. 7A.

FIG. 7C is a cross-sectional view illustrating a step following the stepof FIG. 7B.

FIG. 8A is a cross-sectional view illustrating a step following the stepof FIG. 7C.

FIG. 8B is a cross-sectional view illustrating a step following the stepof FIG. 8A.

FIG. 8C is a cross-sectional view illustrating a step following the stepof FIG. 8B.

FIG. 9 is a cross-sectional view illustrating a configuration of adisplay unit according to Modification 1 of the first embodiment.

FIG. 10A is a cross-sectional view illustrating a method ofmanufacturing the display unit illustrated in FIG. 9 in order of steps.

FIG. 10B is a cross-sectional view illustrating a step following a stepof FIG. 10A.

FIG. 10C is a cross-sectional view illustrating a step following thestep of FIG. 10B.

FIG. 11 is a cross-sectional view illustrating a configuration of aterminal section of a display unit according to Modification 2 of thesecond embodiment.

FIG. 12A is a cross-sectional view illustrating a method ofmanufacturing the display unit illustrated in FIG. 11 in order of steps.

FIG. 12B is a cross-sectional view illustrating a step following a stepof FIG. 12A.

FIG. 12C is a cross-sectional view illustrating a step following thestep of FIG. 12B.

FIG. 12D is a cross-sectional view illustrating a step following thestep of FIG. 12C.

FIG. 13 is a cross-sectional view illustrating a configuration of aterminal section of a display unit according to Modification 3 of thesecond embodiment.

FIG. 14A is a cross-sectional view illustrating a method ofmanufacturing the display unit illustrated in FIG. 13 in order of steps.

FIG. 14B is a cross-sectional view illustrating a step following a stepof FIG. 14A.

FIG. 14C is a cross-sectional view illustrating a step following thestep of FIG. 14B.

FIG. 15A is a cross-sectional view illustrating a step following thestep of FIG. 14C.

FIG. 15B is a cross-sectional view illustrating a step following thestep of FIG. 15A.

FIG. 15C is a cross-sectional view illustrating a step following thestep of FIG. 15B.

FIG. 16A is a perspective view illustrating an appearance viewed fromthe front side of Application example 1 of a display unit using a pixelaccording to the foregoing embodiments and the like.

FIG. 16B is a perspective view illustrating an appearance viewed fromthe rear side of Application example 1 of the display unit using thepixel according to the foregoing embodiments and the like.

FIG. 17 is a perspective view illustrating an appearance of Applicationexample 2.

FIG. 18A is a perspective view illustrating an appearance viewed fromthe front side of Application example 2.

FIG. 18B is a perspective view illustrating an appearance viewed fromthe rear side of Application example 2.

FIG. 19 is a perspective view illustrating an appearance of Applicationexample 3.

FIG. 20 is a perspective view illustrating an appearance of Applicationexample 4.

FIG. 21A illustrates an elevation view of Application example 5 in aclosed state, a left side view thereof, a right side view thereof, a topview thereof, and a bottom view thereof.

FIG. 21B illustrates an elevation view of Application example 5 in anopen state and a side view thereof.

DETAILED DESCRIPTION

Some embodiments of the present disclosure will be described in detailbelow with reference to the drawings. The description will be given inthe following order.

-   1. Whole Configuration of Display Unit-   2. First Embodiment (an example in which a terminal section is    configured of a wiring layer, and a protective film is formed on an    end portion thereof)-   2-1. Configuration of Terminal Section-   2-2. Manufacturing Method-   2-3. Function and Effect-   3. Second Embodiment (an example in which a terminal section has a    laminated structure configured of a wiring layer and a pixel    electrode)-   4. Modification 1 (an example in which a multilayer wiring is    included)-   5. Modification 2 (another example in which a multilayer wiring is    included)-   6. Modification 3 (an example in which a wiring layer has a    laminated structure made of materials having different etching    characteristics)-   7. Application Examples (examples of display units each including a    circuit substrate, and electronic apparatuses)

1. WHOLE CONFIGURATION OF DISPLAY UNIT

FIG. 1 illustrates an example of a planar configuration of a displayunit (display unit 1) according to an embodiment of the presentdisclosure. The display unit 1 may be used, for example, for aninspection monitor or the like, and may have a configuration in which aplurality of pixels (red pixels 10R, green pixels 10G, and blue pixels10B) are arranged, for example, in a state of matrix in a display region110A. A pixel section 10 (see FIG. 3B) may have, for example, red lightemitting elements 30R (the red pixels 10R) emitting red monochromaticlight, green light emitting elements 30G (the green pixels 10G) emittinggreen monochromatic light, and blue light emitting elements 30B (theblue pixels 10B) emitting blue monochromatic light (for any component,see FIG. 3A). The light emitting elements 30R, 30G, and 30B may beconfigured of, for example, after-mentioned organic EL elements.Alternatively, the light emitting elements 30R, 30G, and 30B may beconfigured of inorganic EL elements, semiconductor lasers, LEDs (LightEmitting Diodes), or the like. Around the display region 110A (in aperipheral region 110B), a signal line drive circuit 120 and a scanningline drive circuit 130 that are drivers for displaying an image areprovided.

In the display region 110A, a pixel drive circuit 140 is provided. FIG.2 illustrates an example of the pixel drive circuit 140. The pixel drivecircuit 140 is an active-type drive circuit formed in a layer below anafter-mentioned pixel electrode 31. That is, the pixel drive circuit 140has a drive transistor Tr1, a writing transistor Tr2, a capacitor(retentive capacity) Cs between the transistors Tr1 and Tr2, and thelight emitting element 30R (or one of 30G and 30B) serially connected tothe drive transistor Tr1 between a first power line (Vcc) and a secondpower line (GND). Each of the drive transistor Tr1 and the writingtransistor Tr2 is configured of a general thin film transistor. Theconfiguration thereof is not particularly limited, and may be, forexample, an inverse-stagger structure (a so-called bottom-gate type,that is, a structure in which a gate electrode, a channel layer, and apair of source-drain electrodes are layered in order), or a staggerstructure (a top-gate type, that is, a structure in which a channellayer, a gate electrode, and a pair of source-drain electrodes arelayered in order).

In the pixel drive circuit 140, a plurality of signal lines 120A arearranged in a column direction, and a plurality of scanning lines 130Aare arranged in a row direction. Every intersection of each signal line120A and each scanning line 130A corresponds to one of the lightemitting elements 30R, 30G, and 30B. Each signal line 120A is connectedto the signal line drive circuit 120, and an image signal is suppliedfrom the signal line drive circuit 120 to a source electrode of thewriting transistor Tr2 through the signal line 120A. Each scanning line130A is connected to the scanning line drive circuit 130, and scanningsignals are sequentially supplied from the scanning line drive circuit130 to a gate electrode of the writing transistor Tr2 through thescanning line 130A.

FIG. 3A illustrates planar configurations of the pixel section 10 and aterminal section 40 in an after-mentioned first embodiment. FIG. 3Billustrates cross-sectional configurations taken along a dashed-line I-Iof one pixel (such as the red pixel 10R) configuring the pixel section10 and the terminal section 40 illustrated in FIG. 3A. The semiconductorlayer 20 may be provided, for example, with the foregoing drivetransistor Tr1, the foregoing writing transistor Tr2, and the like. Adisplay layer 30 is provided on a semiconductor layer 20, and has theforegoing light emitting elements 30R, 30G, and 30B.

In the display unit 1 according to this embodiment of the presentdisclosure, the terminal section 40 may be configured of anelectrically-conductive layer 42 (first electrically-conductive layer)formed in the same step as a step of forming a wiring layer configuring,for example, the drive transistor Tr1, specifically, a step of forming agate electrode 21 or a pair of source-drain electrodes 25 (a sourceelectrode 25A and a drain electrode 25B). The terminal section 40 is aconnection section between a lead wiring in the display unit 1 and anexternal circuit (such as a flexible printed circuit).

A description will be given below of the semiconductor layer 20 and thedisplay layer 30 that configure the pixel section 10, and the terminalsection 40.

Configuration of Semiconductor Layer

In the semiconductor layer 20 on the substrate 11, the foregoing drivetransistor Tr1 and the foregoing writing transistor Tr2 are formed. Onthe transistors Tr1 and Tr2, a planarizing insulating film 26 isprovided. Although the transistors Tr1 and Tr2 (referred to as a thinfilm transistor 20A below) may be of a top-gate type or a bottom-gatetype, in this embodiment, description will be given by taking thebottom-gate type thin film transistor 20A as an example. In the thinfilm transistor 20A, the gate electrode 21, a gate insulating film 22,an organic semiconductor film (a channel layer 23) forming a channelregion, an interlayer insulating film 24, and the pair of source-drainelectrodes (the source electrode 25A and the drain electrode 25B) areprovided in order from the substrate 11.

For the substrate 11, for example, a plastic substrate made, forexample, of polyether sulfone, polycarbonate, polyimides, polyamides,polyacetals, polyethylene terephthalate, polyethylene naphthalate,polyetherether ketone, polyolefins, or the like; a metal foil substratemade, for example, of aluminum (Al), nickel (Ni), copper (Cu), stainlesssteel, or the like with a surface subjected to insulation treatment;paper; or the like may be used other than a glass substrate. Further, afunctional film such as a buffer layer to improve adhesibility andflatness and a barrier film to improve gas-barrier characteristics maybe formed on the substrate. Further, if the channel layer 23 is allowedto be formed without heating the substrate 11, for example, by asputtering method or the like, an inexpensive plastic film may be usedfor the substrate 11.

The gate electrode 21 has a role to apply a gate voltage to the thinfilm transistor 20A and to control carrier density in the channel layer23 by the gate voltage. The gate electrode 21 is provided in a selectiveregion on the substrate 11, and may be made, for example, of a simplesubstance of metal such as platinum (Pt), titanium (Ti), ruthenium (Ru),molybdenum (Mo), Cu, tungsten (W), nickel (Ni), Al, and tantalum (Ta),or an alloy thereof. Further, the gate electrode 21 may have a structurein which two or more thereof are layered.

The gate insulating film 22 is provided between the gate electrode 21and the channel layer 23, and may have a thickness, for example, from 50nm to 1 μm both inclusive. The gate insulating film 22 may be formed,for example, of an insulating film including one or more of a siliconoxide film (SiO), a silicon nitride film (SiN), a silicon oxynitridefilm (SiON), a hafnium oxide film (HfO), an aluminum oxide film (AlO),an aluminum nitride film (AlN), a tantalum oxide film (TaO), a zirconiumoxide film (ZrO), a hafnium oxynitride film, a hafnium siliconoxynitride film, an aluminum oxynitride film, a tantalum oxynitridefilm, and a zirconium oxynitride film. The gate insulating film 22 mayhave a single-layer structure, or a laminated structure using two ormore materials such as SiN and SiO. In the case where the gateinsulating film 22 has the laminated structure, interfacecharacteristics with respect to the channel layer 23 are improved, andmixing of impurity (such as moisture) from ambient air into the channellayer 23 is effectively suppressed. The gate insulating film 22 ispatterned in a predetermined shape by etching after coating.Alternatively, depending on the material, pattern formation of the gateinsulating film 22 may be performed by a printing technology such asink-jet printing, screen printing, offset printing, and gravureprinting.

The channel layer 23 is provided on the gate insulating film 22 in ashape of an island, and has a channel region in a position opposed tothe gate electrode 21 between the source electrode 25A and the drainelectrode 25B. The channel layer 23 may have a thickness from 5 nm to100 nm both inclusive, for example. The channel layer 23 may be made,for example, of an organic semiconductor material such as aperi-xanthenoxanthene (PXX) derivative. Examples of the organicsemiconductor material may include polythiophene, poly-3-hexylthiophene[P3HT] obtained by introducing a hexyl group to polythiophene, pentacene[2,3,6,7-dibenzo anthracene], polyanthracene, naphthacene, hexacene,heptacene, dibenzo pentacene, tetrabenzo pentacene, chrysene, perylene,coronene, Terylene, ovalene, quaterrylene, circumanthracene,benzopyrene, dibenzopyrene, triphenylene, polypyrrole, polyaniline,polyacetylene, polydiacetylene, polyphenylene, polyfuran, polyindole,polyvinylcarbazole, polyselenophene, polytellurophene,polyisothianaphthene, polycarbazole, polyphenylene sulfide,polyphenylene vinylene, polyphenylene sulfide, polyvinylene sulfide,polythienylene vinylene, polynaphthalene, polypyrene, polyazulene,phthalocyanine represented by copper phthalocyanine, merocyanine,hemicyanine, polyethylene dioxythiophene, pyridazine, naphthalenetetracarboxylic acid diimide, poly(3,4-ethyleendioxythiophene)/polystyrene sulfonic acid [PEDOT/PSS], 4,4′-biphenyldithiol (BPDT), 4,4′-diisocyanobiphenyl, 4,4′-diisocyano-p-terphenyl,2,5-bis(5′-thioacetyl-2′-thiophenyl)thiophene,2,5-bis(5′-thioacetoxyl-2′-thiophenyl)thiophene, 4,4′-diisocyanophenyl,benzidine(biphenyl-4,4′-diamine), TCNQ (tetracyanoquinodimethane), acharge-transfer complex represented by a tetrathiafulvalene (TTF)-TCNQcomplex, a bisethylene tetrathiafulvalene (BEDTTTF)-perchloric acidcomplex, a BEDTTTF-iodine complex, and a TCNQ-iodine complex,biphenyl-4,4′-dicarboxylic acid, 24-di(4-thiophenylacetylenyl)-2-ethylbenzene, 24-di(4-isocyanophenylacetylenyl)-2-ethylbenzene, dendrimer, fullerene such as C60, C70, C76,C78, and C84, 24-di(4-tiohphenylethynyl)-2-ethylbenzene,2,2″-dihydroxy-1,1′:4′,1″-terphenyl, 4,4′-biphenyl diethanal, 4,4′-biphenyldiol, 4, 4′-biphenyldiisocyanate, 24-diacetynylbenzene,diethylbiphenyl-4,4′-dicarboxylate, benzo[22-c;3,4-c′;5,6-c″]tris[22]dichiol-24,7-trithion, alpha-sexithiophene, tetrathiotetracene,tetraselenotetracene, tetratellurtetracene, poly(3-alkylthiophene),poly(3-thiophene-β-ethanesulfonic acid),poly(N-alkylpyrrole)poly(3-alkylpyrrole), poly(3,4-dialkylpyrrole),poly(2,2′-thienylpyrrole), poly(dibenzothiophene sulfide), andquinacridone. In addition thereto, a compound selected from a groupconsisting of condensed polycyclic aromatic compounds, porphyrin-basedderivatives, phenylvinylidene-based conjugate-system oligomers, andthiophene-based conjugate-system oligomers may be used. Further, amixture of an organic semiconductor material and an insulating polymermaterial may be used.

The channel layer 23 may be formed by a vacuum evaporation method.However, the channel layer 23 may be preferably formed, for example, bya coating and printing process by dissolving any of the foregoingmaterials, for example, in an organic solvent and using the resultant asan ink solution. One reason for this is that the coating and printingprocess reduces cost more than the vacuum evaporation method, and iseffective in improving throughput. Specific examples of the coating andprinting process may include methods such as cast coating, spin coating,spray coating, inkjet printing, relief printing, flexo printing, screenprinting, gravure printing, and gravure offset printing.

The source electrode 25A and the drain electrode 25B are provided on thechannel layer 23 being separated from each other, and are electricallyconnected to the channel layer 23. As a material configuring the sourceelectrode 25A and the drain electrode 25B, a metal material, a metalloidmaterial, an inorganic semiconductor material, etc. may be used.Specific examples thereof may include the electrically-conductive filmmaterials mentioned for the foregoing gate electrode 21; aluminum (Al),gold (Au), silver (Ag), indium tin oxide (ITO), and molybdenum oxide(MoO); and an alloy of any of these kinds of metal. The source electrode25A and the drain electrode 25B are configured of simple substance ofany of the foregoing metal or alloy thereof. The source electrode 25Aand the drain electrode 25B may have a single layer structure, or mayhave a structure obtained by laminating two or more of the foregoingmaterials. Examples of the laminated structure may include a laminatedstructure such as [Ti/Al/Ti] and [Mo/Al].

The planarizing insulating film 26 planarizes the surface of thesubstrate 11 on which the thin film transistor 20A is formed. Examplesof constituent materials of the planarizing insulating film 26 mayinclude an organic material such as polyimide and an inorganic materialsuch as silicon oxide (SiO₂).

Configuration of Display Layer

The display layer 30 includes the red light emitting element 30R (or oneof the green light emitting element 30G and the blue light emittingelement 30B), and is provided on the semiconductor layer 20,specifically, on the planarizing insulating film 26. The red lightemitting element 30R is a light emitting element in which a pixelelectrode 31 as an anode, an interelectrode insulating film 32 (dividingwall), an organic layer 33 including a light emitting layer, and acounter electrode 34 as a cathode are layered in order from thesemiconductor layer 20. A sealing substrate 36 is bonded onto thecounter electrode 34 with a sealing layer 35 in between. The thin filmtransistor 20A and the red light emitting element 30R are electricallyconnected to the pixel electrode 31 through a connection hole 26Aprovided in the planarizing insulating film 26.

The pixel electrode 31 also has a function as a reflection layer, andmay desirably have high reflectance as much as possible in order toimprove light emission efficiency. In particular, in the case where thepixel electrode 31 is used as an anode, the pixel electrode 31 may bedesirably made, for example, of a material having high hole-injectioncharacteristics. Examples of such a material of the pixel electrode 31may include simple substance of a metal element such as aluminum (Al),chromium (Cr), gold (Au), platinum (Pt), nickel (Ni), copper (Cu),tungsten (W), and silver (Ag); and an alloy thereof. On the surface ofthe pixel electrode 31, a transparent electrode having a large workfunction may be preferably layered. In this embodiment of the presentdisclosure, description will be given below of a case, as an example, inwhich the pixel electrode 31 has a laminated structure configured of alayer (a reflective electrode film 31A) made of the above-describedmaterial having a reflective function such as Al and a layer (atransparent electrode film 31B) made of a transparentelectrically-conductive material such as an oxide of indium and tin(ITO).

The interelectrode insulating layer 32 is configured to secureinsulation between the pixel electrode 31 and the counter electrode 34,and to allow a light emission region to have a desirable shape. Theinterelectrode insulating layer 32 may be made, for example, of aphotosensitive resin. The interelectrode insulating film 32 is providedonly around the pixel electrode 31. A region, of the pixel electrode 31,exposed from the interelectrode insulating film 32 is the light emissionregion. It is to be noted that, although the organic layer 33 and thecounter electrode 34 are also provided on the interelectrode insulatingfilm 32, light is emitted only from the light emission region.

For example, the organic layer 33 may have a configuration in which ahole injection layer, a hole transport layer, a light emission layer, anelectron transport layer, and an electron injection layer are laminatedin order from the pixel electrode 31. These layers may be provided asnecessary. Configurations of the respective layers forming the organiclayer 33 may differ according to emission colors of the light emittingelements 30R, 30G, and 30B. The hole injection layer improves holeinjection efficiency, and is a buffer layer to prevent leakage. The holetransport layer improves transport efficiency of holes to the lightemission layer. In the light emission layer, when an electric field isapplied, recombination of electrons and holes occurs, and thereby, lightis generated. The electron transport layer improves transport efficiencyof electrons to the light emission layer. The electron injection layerimproves electron injection efficiency.

The counter electrode 34 is made, for example, of an alloy of aluminum(Al), magnesium (Mg), calcium (Ca), or sodium (Na). In particular, analloy (Mg—Ag alloy) of magnesium and silver may be preferable, sincesuch an alloy has both electric conductivity and small absorption in athin film. Although the ratio between magnesium and silver in the Mg—Agalloy is not limited, the film thickness ratio between Mg and Ag may bedesirably in a range from 20:1 to 1:1 both inclusive. Further, as amaterial of the counter electrode 34, an alloy (Al—Li alloy) of aluminum(Al) and lithium (Li) may be used.

The sealing layer 35 may have, for example, a laminated structureconfigured of a layer made of silicon nitride (SiN_(x)), silicon oxide(SiO_(x)), a metal oxide, or the like, and a layer made of athermosetting resin, an ultraviolet curable resin, or the like. Forexample, the sealing substrate 36 provided with a light-blocking filmand a color filter may be bonded onto the sealing layer 35.

Configuration of Terminal Section

As described above, the terminal section 40 connects various wirings inthe display unit 1 to an external circuit. In this embodiment, theterminal section 40 may be configured of the electrically-conductivelayer 42 (the first electrically-conductive layer) formed in the samestep as of the step of forming the wiring layer provided in thesemiconductor layer 20 such as the gate electrode 21 or the sourceelectrode 25A and the drain electrode 25B. In other words, in thisembodiment, the terminal section 40 may be configured of theelectrically-conductive layer 42 (the first electrically-conductivelayer) formed of the same material as the material of the wiring layerprovided in the semiconductor layer 20 such as the gate electrode 21 orthe source electrode 25A and the drain electrode 25B. Alternatively, theterminal section 40 may have a configuration in which anelectrically-conductive layer (a second electrically-conductive layer)formed in the same step as a step of forming the pixel electrode 31 islaminated on the electrically-conductive layer 42.

It is to be noted that, in the display unit 1 according to thisembodiment of the present disclosure, a material included in the wiringlayer (the gate electrode 21 or one of the source electrode 25A and thedrain electrode 25B) formed in the same step as of the step of formingthe electrically-conductive layer 42 in the terminal section 40 and amaterial included in the pixel electrode 31 in the display layer 30 areremovable by the same etchant (these materials have the same etchingcharacteristics). Examples of etchant types may includeacetic-acid-phosphoric-acid-nitric-acid-based aqueous solution,hydrofluoric-acid-nitric-acid-based aqueous solution, andammonia-hydrogen-peroxide-based aqueous solution. For example, aluminum(Al), silver (Ag), or molybdenum (Mo) may be removed by theacetic-acid-phosphoric-acid-nitric-acid-based aqueous solution. Forexample, tantalum (Ta) or tungsten (W) may be removed by thehydrofluoric-acid-nitric-acid-based aqueous solution. For example,titanium (Ti), titanium nitride (TiN), or copper (Cu) may be removed bythe ammonia-hydrogen-peroxide-based aqueous solution.

2. FIRST EMBODIMENT 2-1. Configuration of Terminal Section

The display unit 1 in the first embodiment of the present disclosure hasa configuration in which, as illustrated in FIG. 3B, the terminalsection 40 is configured of the electrically-conductive layer 42 formedin the same step as of the step of forming the wiring layer provided inthe semiconductor layer 20, that is, in this example, the sourceelectrode 25A and the drain electrode 25B. In this embodiment, in theterminal section 40, an insulating film 41, the electrically-conductivelayer 42, and an insulating film 43 having an opening 43A are laminatedin order from the substrate 11. The end portion of theelectrically-conductive layer 42, specifically, a portion from acircumferential edge portion of the top surface to side surfaces of theelectrically-conductive layer 42 is covered with a protective film 44.

The terminal section 40 in the display unit 1 in this embodiment may bemanufactured as follows.

2-2. Manufacturing Method

As illustrated in FIG. 4A, the semiconductor layer 20 and the terminalsection 40 are formed on the substrate 11 by a general method. First, ametal film to become the gate electrode 21 may be formed on the wholesurface of the substrate 11, for example, by a sputtering method, avacuum evaporation method, or the like. Next, the metal film may bepatterned, for example, by photolithography and etching, and thereby,the gate electrode 21 is formed. Subsequently, the gate insulating film22, the insulating film 41, and the channel layer 23 are formed in orderon the whole surfaces of the substrate 11 and the gate electrode 21.Specifically, the whole surface of the substrate 11 may be coated withthe foregoing material of the gate insulating film such as PVP(polyvinylpyrrolidone) solution, for example, by spin coating, and theresultant is dried. Thereby, the gate insulating film 22 in the pixelsection 10 and the insulating film 41 in the terminal section 40 areformed. Next, an organic semiconductor material such as PXX compoundsolution is applied onto this gate insulating film 22. Thereafter, theapplied organic semiconductor material is heated, and thereby, thechannel layer 23 is formed on the gate insulating film 22.

Subsequently, the interlayer insulating film 24 is formed on the channellayer 23. Thereafter, a metal film is formed on the channel layer 23,the interlayer insulating film 24, and the insulating film 41.Specifically, for example, a laminated film having a configuration of[Mo/Al/Mo] may be formed, for example, by a sputtering method. Next, thesource electrode 25A, the drain electrode 25B, and theelectrically-conductive layer 42 may be formed by etching with the use,for example, of a photolithography method.

Next, as illustrated in FIG. 4B, for example, SiN may be formed as acontinuous film 44P on the interlayer insulating film 24, the sourceelectrode 25A, the drain electrode 25B, and the electrically-conductivelayer 42 by a sputtering method. Thereafter, as illustrated in FIG. 4C,the protective film 44 is formed by removing a portion of the continuousfilm 44P formed on the pixel section 10 by dry etching. Subsequently, asillustrated in FIG. 4D, a photosensitive resin such as polyimide isapplied onto the pixel section 10, the planarizing insulating film 26 isformed and patterned into a predetermined shape by exposure anddevelopment, the connection hole 26A is formed, and the resultant isfired. Next, a metal film 31P having, for example, a configuration of[Al/ITO] may be formed on the planarizing insulating film 26 and theprotective film 44 in the terminal section 40, for example, by asputtering method.

Subsequently, as illustrated in FIG. 5A, portions of the metal film 31Pon the whole surface of the terminal section 40 and part of the pixelsection 10 are selectively removed by wet etching to form the pixelelectrode 31 that is separated from each of the light emitting elements30R, 30G, and 30B. Next, as illustrated in FIG. 5B, the protective film42 in the terminal section 40 may be removed by dry etching with theuse, for example, of SF6 to form the opening 43A to become a connectionsection with respect to the external circuit. Subsequently, asillustrated in FIG. 5C, an insulating film is formed on the wholesurfaces of the pixel section 10 and the terminal section 40, andsubsequently, the insulating film is processed to form the window-likeinterelectrode insulating film 32 defining the light emission region andthe insulating film 43. Thereafter, the organic layer 33 including thelight emission layer, and the counter electrode 34 are formed in thepixel section 10, for example, by an evaporation method. Thereafter, thesealing substrate 36 is bonded thereto with the sealing layer 35 inbetween. Finally, an FPC for connecting with the external circuit ismounted on the terminal section 40, and thereby, the display unit 1 iscompleted.

Such a display unit 1 is applicable to a display unit of an electronicapparatus in any field for displaying an image signal inputted fromoutside or an image signal generated inside as an image or a video suchas a television, a digital camera, a notebook personal computer, aportable terminal device such as a mobile phone, and a video camcorderin addition to an inspection monitor.

2-3. Function and Effect

In general, as wiring materials of a gate electrode, source and drainelectrodes, or the like of the drive transistor Tr1 (or the writingtransistor Tr2) configuring a display unit, metal containing Al as amain component may be preferably used in terms of volume resistivity andprocessability of the wiring materials. Further, by using a metalmaterial having high reflectance such as Al and Ag as a material of apixel electrode in a light emitting element in a top-emission typeorganic EL display unit, high light emission efficiency is obtained.However, in a case where the foregoing wiring layer and the pixelelectrode are made of the same material or materials dissolvable in thesame etchant, and a terminal section connecting various wirings to anexternal circuit is made of the same material as that of the wiringlayer configuring a pixel section, the surface of anelectrically-conductive layer forming the terminal section is damaged oretched in a step of processing the wiring layer. Therefore, the terminalsection has not been allowed to be normally formed, and mounting faults,an increase in resistance value of the terminal section, and the likehave occurred. Accordingly, there have been disadvantages such asdecrease in manufacturing yield, and decrease in reliability due toperformance variations.

In contrast, in this embodiment, the metal film formed in the same stepas of the step of forming the wiring layer (in this case, the sourceelectrode 25A and the drain electrode 25B) forming the semiconductorlayer 20 is formed as the electrically-conductive layer 42 in theterminal section 40, and thereafter, the protective film 44 is formed onthe electrically-conductive layer 42. The protective film 44 is formedusing the material that is not removable by the etchant used for etchingthe electrically conductive layer 42. Thereby, in the step of processingthe pixel electrode 31 formed of the material that is removable by thesame etchant as that of the source electrode 25A, the drain electrode25B, and the electrically-conductive layer 42, that is, the materialhaving the same etching characteristics as those of the source electrode25A, the drain electrode 25B, and the electrically-conductive layer 42,damage of the electrically-conductive layer 42 is prevented.

As described above, in the display unit 1 and the method ofmanufacturing the display unit 1 in this embodiment, the metal film thatis formed in the same step and is made of the same material as those ofthe wiring layer formed in the semiconductor layer 20 is formed as theelectrically-conductive layer 42 configuring the terminal section 40,and thereafter, the protective film 44 is formed on theelectrically-conductive layer 42. Thereby, in the subsequent etchingstep, damage of the electrically-conductive layer 42 is prevented, andthe normal terminal section 40 is formed. Therefore, variations incharacteristics are decreased, and manufacturing yield is improved. Thatis, a highly-reliable display unit is provided.

Description will be given below of a second embodiment and Modifications1 to 3. It is to be noted that, in the following description, for thesame components as the components in the first embodiment, the samereferential symbols are affixed thereto, and description thereof will beomitted as appropriate.

3. SECOND EMBODIMENT

FIG. 6 illustrates a cross-sectional configuration of a terminal section50 in a display unit 2 in the second embodiment of the presentdisclosure. The terminal section 50 is different from the foregoingfirst embodiment in that an electrically-conductive layer 52 formed inthe same step as a step of forming the pixel electrode 31 is laminatedon an electrically-conductive layer 51 formed in the same step as a stepof forming the wiring layer formed in the semiconductor layer 20.

The terminal section 50 has the electrically-conductive layer 51 formedin the same step as the step of forming the wiring layer (in thisexample, the source electrode 25A and the drain electrode 25B) as in thefirst embodiment. On the electrically-conductive layer 51, theelectrically-conductive layer 52 formed in the same step as of the stepof forming the pixel electrode 31 is laminated. As in the firstembodiment, the pixel electrode 31 in this embodiment has a laminatedstructure configured of a layer (the reflective electrode film 31A) madeof a material (such as Al and an Al alloy) having the same etchingcharacteristics as those of the wiring layer such as the sourceelectrode 25A and the drain electrode 25B and a layer (the transparentelectrode film 31B) formed with the use of a transparentelectrically-conductive material such as ITO. Therefore, as with thepixel electrode 31, the electrically-conductive layer 52 in the terminalsection 50 has a configuration in which a layer (anelectrically-conductive layer 52A) made of a material having the sameetching characteristics as those of the source electrode 25A and thedrain electrode 25B, that is, a material having the same etchingcharacteristics as those of the electrically-conductive layer 51, and alayer (a transparent electrode layer 52B) made of a transparentelectrically-conductive material are laminated in this order. However,in the terminal section 50 in this embodiment, part of the transparentelectrode material layer 52B on the surface thereof, specifically, aportion, in an opening section 53A, to become a connection surface withrespect to an external circuit is removed, and theelectrically-conductive layer 52A is exposed.

The terminal section 50 in the display unit 2 in this embodiment may bemanufactured as follows. First, by a method similar to that in theforegoing first embodiment, as illustrated in FIG. 7A, layers up to thesource electrode 25A, the drain electrode 25B, and theelectrically-conductive layer 51 are formed. Subsequently, asillustrated in FIG. 7B, after the planarizing insulating film 26 isformed, metal films 31P and 52 having, for example, a configuration of[Al (52A)/ITO (52B)] are formed on the surfaces of the drain electrode25B and the planarizing insulating film 26 and on theelectrically-conductive layer 51 in the terminal section 50.

Next, ITO is selectively removed to obtain a predetermined shape asillustrated in FIG. 7C. At this time, a portion of ITO (52B) in theterminal section 50 is not removed. Subsequently, as illustrated in FIG.8A, the pixel electrode 31 and the electrically-conductive layer 52 (52Aand 52B) are processed. Thereafter, as illustrated in FIG. 8B, thewindow-like interelectrode insulating film 32 defining the lightemission region and the insulating film 53 having the opening 53A areformed. Next, as illustrated in FIG. 8C, the electrically-conductivelayer 52B in the opening 53A is etched, specifically, is removed toobtain an opening having the substantially-same shape as that of theopening 53A, and thereby, the electrically-conductive layer 52 iselectrically conducted to the external circuit. Thereafter, the organiclayer 33 including the light emission layer is formed in the pixelsection 10 by an evaporation method. Thereafter, the sealing substrate36 is bonded thereto with the sealing layer 35 in between. Finally, anFPC for connecting with the external circuit is mounted on the terminalsection 40, and thereby, the display unit 2 is completed.

In a display unit in which a pixel electrode has a laminated structureconfigured of a metal film and a transparent electrode film, in the casewhere this pixel electrode is used as a terminal section connected to anexternal circuit, there are disadvantages that an average mountingresistance value is increased more compared to in a display unit notusing the pixel electrode as a terminal section, and that variations inresistance value are significantly increased and display unevennessoccurs. One reason for this is that, in the case where a reflectiveelectrode film and a transparent electrode, for example, an Al—Ni alloyand ITO are directly contacted, a partial ohmic contact section throughAl₃Ni-layer particles and a non-ohmic contact section through an Aloxide film exist in a mixed manner. Another reason for this may be thatan electrically-conductive filler of a mounted member and the surface ofthe terminal section are point-contacted.

In contrast, in this embodiment, the terminal section 50 has thelaminated structure configured of the electrically-conductive layer 51formed in the same step as of the step of forming the wiring layer andthe electrically-conductive layer 52 formed in the same step as of thestep of forming the pixel electrode 31. In the manufacturing stepthereof, at the time of processing the pixel electrode 31, thetransparent electrode film 52B provided in the electrically-conductivelayer 52 in the terminal section 50 is left, and is used as a protectivefilm at the time of etching the reflective electrode film 52A. Thereby,the electrically-conductive layer 51 and the electrically-conductivelayer 52 (the reflective electrode film 52A) configuring the terminalsection 50 are prevented from being damaged by the etching. Further, thetransparent electrode film 52B on the top surface of the terminalsection 50 is removed after patterning the pixel electrode 31. Thereby,increase in the resistance value in the terminal section 50 isprevented.

As described above, in the display unit 2 and the method ofmanufacturing the display unit 2 in this embodiment, by using thetransparent electrode film 52B as a protective film at the time ofprocessing the reflective electrode film 52A, the terminal section 50 isnormally formed. Further, by finally removing the transparent electrodefilm 52B in the terminal section 50, increase in the resistance value inthe terminal section 50 is prevented. Therefore, variations incharacteristics are decreased, and manufacturing yield is improved. Thatis, a highly-reliable display unit is allowed to be provided.

4. MODIFICATION 1

FIG. 9 illustrates cross-sectional configurations of a pixel section 60and the terminal section 40 of a display unit 3 in a modification of theforegoing first embodiment. The display unit 3 is different from thedisplay unit in the foregoing first embodiment in that the semiconductorlayer 20 configuring the pixel section 60 is configured of a multilayerwiring. This semiconductor layer 20 may have a configuration in which aninterlayer insulating film 61 formed, for example, of a resin materialsuch as polyimide and a wiring layer 62 formed of a metal materialsimilar to that of the gate electrode 21, the source electrode 25A, andthe drain electrode 25B are layered between respective layersconfiguring the thin film transistor 20A and the planarizing insulatingfilm 26. It is to be noted that, for forming the electrically-conductivelayer 42 configuring the terminal section 40 in this modification, thewiring layer 62 may be used other than the gate electrode 21 or thesource electrode 25A and the drain electrode 25B. In this case, thewiring layer 62 is made of a material having the same etchingcharacteristics as those of the pixel electrode 31 (in particular, thereflective electrode film 31A).

The display unit 3 in this modification may be manufactured as follows.First, the source electrode 25A, the drain electrode 25B, and theelectrically-conductive layer 42 are formed as illustrated in FIG. 10Aby a method similar to that in the foregoing first embodiment, andthereafter, the protective film 44 is formed in the terminal section 40.Subsequently, as illustrated in FIG. 10B, the interlayer insulating film61 and the wiring layer 62 are formed on the interlayer insulating film24, the source electrode 25A, and the drain electrode 25B, andthereafter, the planarizing insulating film 26 and a pixel electrodefilm 31P are formed in order. Further, the pixel electrode film 31P isalso formed on the protective film 44 in the terminal section 40.

Next, as illustrated in FIG. 10C, a portion of the pixel electrode film31P on the whole surface of the terminal section 40 is removed by wetetching, and the pixel section 10 is processed. Thereafter, a portion,of the protective film 44 in the terminal section 40, to be a connectionsection with respect to an external circuit may be selectively removedby dry-etching with the use, for example, of SF6 or the like.Subsequently, as illustrated in FIG. 10C, the insulting film 43 isformed on the window-like interelectrode insulating film 32 defining thelight emission region and the terminal section 40. Thereafter, theorganic layer 33 including the light emission layer is formed in thepixel section 60 by an evaporation method, and thereafter, the sealingsubstrate 36 is bonded thereto with the sealing layer 35 in between.Finally, an FPC for connecting with the external circuit is mounted onthe terminal section 40, and thereby, the display unit 3 is completed.

5. MODIFICATION 2

FIG. 11 illustrates a cross-sectional configuration of a terminalsection 70 of a display unit 4 in a modification of the foregoing secondembodiment. The display unit 4 is different from the display unit in theforegoing second embodiment in that the semiconductor layer 20 has amultilayer wiring structure as in the foregoing Modification 1, and anelectrically-conducive layer configuring the terminal section 70 has atrilayer structure. This electrically-conducive layer may have, forexample, a configuration in which an electrically-conducive layer 72formed in the same step as of the step of forming the source electrode25A and the drain electrode 25B, an electrically-conducive layer 75formed in the same step as of the step of forming the wiring layer 62,and an electrically-conducive layer 73 formed in the same step as thestep of forming the pixel electrode 31 are layered in this order. It isto be noted that, the electrically-conducive layer 72 may be formed inthe same step as that of the gate electrode 21.

The display unit 4 in this modification may be manufactured as follows.First, the source electrode 25A, the drain electrode 25B, and theelectrically-conductive layer 72 on an insulating film 71 are formed asillustrated in FIG. 12A by a method similar to that in the foregoingsecond embodiment. Subsequently, as illustrated in FIG. 12B, theinterlayer insulating film 61 and the wiring layer 62 are formed on theinterlayer insulating film 24, the source electrode 25A, the drainelectrode 25B, and the electrically-conductive layer 51; and theelectrically-conducive layer 75 is formed on the electrically-conductivelayer 72 in the terminal section 70.

Next, as illustrated in FIG. 12C, the planarizing insulating film 26,the pixel electrode 31, and the electrically-conducive layer 73 areformed. Thereafter, as illustrated in FIG. 12D, the window-likeinterelectrode insulating film 32 defining the light emission region andan insulting film 74 are formed. Further, out of theelectrically-conducive layer 73 (a reflective electrode film 73A and atransparent electrode film 73B) formed concurrently with the pixelelectrode 31 in the terminal section 70, the transparent electrode film73B that has served as a protective film is removed. Thereafter, theorganic layer 33 included in the pixel section 60 is formed by anevaporation method, and thereafter, the sealing substrate 36 is bondedthereto with the sealing layer 35 in between. Finally, an FPC forconnecting with the external circuit is mounted on the terminal section70, and thereby, the display unit 4 is completed.

Display units are desired to further be larger in size and have higherresolution. In the case where a display unit becomes larger in size,signal delay occurs due to a load resulting from a wiring resistance anda parasitic capacitance. Further, in the case of achieving higherresolution, as the number of pixels is increased, density of a wiringlayer in which a drive wiring and a signal line are formed is increasedparticularly in an organic EL display unit, and thereby, the number ofshort-circuit faults is increased, and manufacturing yield is lowered,disadvantageously. One method to resolve the foregoing disadvantages maybe a method to allow a layer in which various wirings are formed to havea multilayer structure. In a case of achieving the multilayer structureof the wiring layer in the embodiments of the present application, thephotosensitive resin such as polyimide having low electric constant isused between the wiring layers having the multilayer structure is usedin order to avoid signal delay. However, the foregoing resin-basedmaterials have low resistance to dry etching. Therefore, in the casewhere the wiring layer on the photosensitive interlayer insulating resinis processed by dry etching, for example, a hollow may be created in theinsulating film leading to short-circuit between the upper and lowerwiring layers, or appearance unevenness may occur due to roughness ofthe surface of the insulating film. Therefore, for example,manufacturing yield may be easily lowered, and quality variations andthe like may easily occur.

Therefore, the wiring layer 62 added in order to achieve multilayerwiring structure may be preferably made of a material processable by wetetching such as laminated metal having a configuration of [Mo/Al].According to Modifications 1 and 2, for example, in Modification 1, theelectrically-conductive layer 42 in the terminal section 40 is formed inthe same step as of the step of forming the gate electrode 21, of thestep of forming the source electrode 25A and the drain electrode 25B, orof the step of forming the wiring layer 62, and thereafter, theprotective film 44 is formed on the electrically-conductive layer 42. InModification 2, the electrically-conducive layer configuring theterminal section 70 has a trilayer structure (configured of theelectrically-conducive layers 72, 75, and 73), and in the step offormation thereof, the transparent electrode film 73B is formed in theuppermost layer. Therefore, in the case where the semiconductor layer 20has the multilayer wiring structure including the interlayer insulatingfilm 61 formed of the photosensitive resin material, theelectrically-conducive layer 42 of the terminal section 40 (or theelectrically-conductive layers 72, 75, and 73 in the terminal section70) is prevented from being damaged by etching. Therefore, a larger-sizeand high-definition display unit that has high manufacturing yield andsuperior reliability is provided.

6. MODIFICATION 3

FIG. 13 illustrates a cross-sectional configuration of a terminalsection 80 of a display unit 5 in a modification of the foregoing secondembodiment. The display unit 5 has a configuration in which each of thesource electrode 25A and the drain electrode 25B is configured of alaminated structure made of different metal materials having differentetching characteristics. Specifically, in the source electrode 25A andthe drain electrode 25B, for example, an Al alloy and Ti (or W) may belaminated in order from the substrate 11. In an electrically-conductivelayer in the terminal section 80 formed in the same step as of the stepof forming the source electrode 25A and the drain electrode 25B, anelectrically-conducive layer 82A made of an Al alloy and anelectrically-conducive layer 82B made of Ti (or W) are also laminated inthis order.

The display unit 5 in this modification may be manufactured as follows.First, the source electrode 25A, the drain electrode 25B, and anelectrically-conductive layer 82 (the electrically-conductive layers 82Aand 82B) are formed as illustrated in FIG. 14A by a method similar tothat in the foregoing first embodiment. At this time, each of the sourceelectrode 25A, the drain electrode 25B, and the electrically-conductivelayer 82 (the electrically-conductive layers 82A and 82B) has alaminated structure made of metal materials having etchantcharacteristics different from those of the material of the wiring layer62, that may be a laminated structure of [Ti/Al], for example.Subsequently, as illustrated in FIG. 14B, the interlayer insulating film61 and the metal film 62A are formed on the interlayer insulating film24, the source electrode 25A, the drain electrode 25B, and theelectrically-conducive layer 82. Next, as illustrated in FIG. 14C, themetal film 62A in the pixel section 60 is processed to form the wiringlayer 62, and the metal film 62A in the terminal section 80 is removed.At this time, the electrically-conducive layer 82B (the Ti layer in thelaminated structure of [Ti/Al]) serves as an etching protective film.

Subsequently, as illustrated in FIG. 15A, after the planarizinginsulating film 26 is formed, the pixel electrode film 31P is formed onthe whole surfaces of the planarizing insulating film 26 and theterminal section 80. Next, as illustrated in FIG. 15B, the pixelelectrode film 31P is patterned to form the pixel electrode 31, and aportion of the pixel electrode film 31P in the terminal section 80 isremoved. Subsequently, as illustrated in FIG. 15C, the window-likeinterelectrode insulating film 32 defining the light emission region andan insulting film 83 on the terminal section 80 are formed by formingand processing an insulating film. Thereafter, the organic layer 33including the light emission layer is formed in the pixel section 60 byan evaporation method, and thereafter, the sealing substrate 36 isbonded thereto with the sealing layer 35 in between. Finally, an FPC forconnecting with an external circuit is mounted on the terminal section80, and thereby, the display unit 5 is completed.

As described above, in the case where any of the wiring layers (the gateelectrode 21, the source electrode 25A, the drain electrode 25B, and thewiring layer 62) formed in the semiconductor layer 20 has a laminatedstructure made of materials having different etching characteristics, inparticular, in the case where a material of the upper layer thereof hasetching characteristics different from those of the pixel electrode 31,the terminal section 80 is normally formed without separately forming aprotective film as in the foregoing first embodiment and Modification 1.

7. APPLICATION EXAMPLES

The display units 1 to 5 explained above in the first and the secondembodiments and Modifications 1 to 3 may be suitably used, for example,as the following electronic apparatuses.

Application Example 1

FIG. 16A illustrates an appearance of a smartphone from the front sidethereof, and FIG. 16B illustrates an appearance from the rear sidethereof. The smartphone may include, for example, a display section 610(the display unit 1), a non-display section (a package) 620, and anoperation section 630. The operation section 630 may be provided on thefront surface of the non-display section 620 as illustrated in FIG. 16A,or may be provided on the top surface of the non-display section 620 asillustrated in FIG. 16B.

Application Example 2

FIG. 17 illustrates an appearance of a television according toApplication example 2. The television may have, for example, an imagedisplay screen section 200 including a front panel 210 and a filterglass 220. The image display screen section 200 corresponds to any ofthe foregoing display units.

Application Example 3

FIG. 18A illustrates an appearance of a digital camera according toApplication example 3 that is viewed from the front side, and FIG. 18Billustrates an appearance thereof that is viewed from the rear side. Thedigital camera may have, for example, a light emitting section 310 for aflash, a display section 320 as any of the foregoing display units, amenu switch 330, and a shutter button 340.

Application Example 4

FIG. 19 illustrates an appearance of a notebook personal computeraccording to Application example 4. The notebook personal computer mayhave, for example, a main body 410, a keyboard 420 for operation ofinputting characters and the like, and a display section 430 as any ofthe foregoing display units.

Application Example 5

FIG. 20 illustrates an appearance of a video camcorder according toApplication example 5. The video camcorder may have, for example, a mainbody 510, a lens 520 for shooting a subject provided on the front sidesurface of the main body 510, a start-stop switch 530 for shooting, anda display section 540 as any of the foregoing display units.

Application Example 6

FIG. 21A illustrates an elevation view of a mobile phone according toApplication example 6 in a closed state, a left side view thereof, aright side view thereof, a top view thereof, and a bottom view thereof.FIG. 21B illustrates an elevation view of the mobile phone in an openstate and a side view thereof. In the mobile phone, for example, anupper package 710 and a lower package 720 may be jointed by a jointsection (a hinge section) 730. The mobile phone may have a display 740,a sub-display 750, a picture light 760, and a camera 770. One of thedisplay 740 and the sub-display 750 corresponds to any of the foregoingdisplay units.

While the present disclosure has been described with reference to thefirst and the second embodiments, Modifications 1 to 3, and theapplication examples, the present disclosure is not limited to theforegoing embodiments and the like, and various modifications may bemade. For example, the material, the thickness, the film-forming method,the film-forming conditions, and the like of each layer are not limitedto those described in the foregoing embodiments and the like, and othermaterials, other thicknesses, other film-forming methods, and otherfilm-forming conditions may be adopted.

It is possible to achieve at least the following configurations from theabove-described example embodiments and the modifications of thedisclosure.

(1) A display unit including:

a display layer including a pixel electrode;

a semiconductor layer provided in a layer below the display layer, thesemiconductor layer including a wiring layer that includes a materialremovable by an etchant by which the pixel electrode is also removable;and

a terminal section configured to electrically connect the semiconductorlayer to an external circuit, the terminal section including a firstelectrically-conductive layer made of a material same as a material ofthe wiring layer.

(2) The display unit according to (1), wherein

the semiconductor layer includes a gate electrode and a pair ofsource-drain electrodes, and

the terminal section is configured of the first electrically-conductivelayer made of a material same as a material of one of the gate electrodeand the pair of source-drain electrodes.

(3) The display unit according to (2), wherein

the semiconductor layer includes a multilayer wiring layer, and

the terminal section is configured of the first electrically-conductivelayer made of a material same as a material of a metal film configuringthe multilayer wiring layer.

(4) The display unit according to (3), wherein the terminal section isconfigured of one of the first electrically-conductive layer and alaminated structure including the first electrically-conductive layerand a second electrically-conductive layer, the firstelectrically-conductive layer being made of one or more materials sameas the material of the gate electrode, the material of the pair ofsource-drain electrodes, and the material of the metal film, the secondelectrically-conductive layer including a material configuring the pixelelectrode.(5) The display unit according to (4), wherein

each of the pixel electrode and the second electrically-conductive layerin the terminal section has a laminated structure including atransparent electrode film and a reflective electrode film, and

the transparent electrode film in the second electrically-conductivelayer configuring the terminal section includes an opening.

(6) The display unit according to any one of (1) to (5), wherein theterminal section has a protective film at least on both ends of theterminal section.

(7) The display unit according to any one of (1) to (6), wherein theetchant is one of an acetic-acid-phosphoric-acid-nitric-acid-basedaqueous solution, a hydrofluoric-acid-nitric-acid-based aqueoussolution, and an ammonia-hydrogen-peroxide-based aqueous solution.(8) The display unit according to any one of (1) to (7), wherein theterminal section includes one or more of aluminum (Al), silver (Ag), andmolybdenum (Mo).(9) The display unit according to any one of (1) to (8), wherein theterminal section includes one or both of tantalum (Ta) and tungsten (W).(10) The display unit according to any one of (1) to (9), wherein theterminal section includes one or more of titanium (Ti), titanium nitride(TiN), and copper (Cu).(11) The display unit according to any one of (1) to (10), wherein oneor both of the pixel electrode and the wiring layer have a configurationin which layers having different etching characteristics are laminated.(12) The display unit according to any one of (1) to (11), wherein thepixel electrode has a configuration in which indium tin oxide (ITO) andone of aluminum (Al) and an aluminum alloy are laminated.(13) The display unit according to any one of (1) to (12), wherein thewiring layer has a laminated structure in which a Ti layer, an Al layer,and a Ti layer are laminated in order.(14) The display unit according to any one of (1) to (13), wherein thesemiconductor layer includes a gate electrode, a semiconductor film, anda pair of source-drain electrodes in order, or includes a semiconductorfilm, a gate electrode, and a pair of source-drain electrodes in order.(15) A method of manufacturing a display unit, the method including:

forming a wiring layer in a semiconductor layer on a substrate, andforming a first electrically-conductive layer in a terminal section, thefirst electrically-conductive layer being made of a material same as amaterial of the wiring layer;

forming, as a continuous film, a pixel electrode on the semiconductorlayer and the first electrically-conducive layer, the pixel electrodeconfiguring a display layer, and the pixel electrode being made of amaterial removable by an etchant by which the wiring layer is alsoremovable; and

removing part or all of the pixel electrode on the firstelectrically-conducive layer to from the terminal section.

(16) The method according to (15), further including: between theforming of the wiring layer and the first electrically-conducive layerand the forming of the pixel electrode,

forming, as a continuous film, a protective film on the wiring layer andthe first electrically-conducive layer; and

removing the protective film on the wiring layer.

(17) The method according to (15) or (16), wherein the pixel electrodeis formed as a second electrically-conducive layer on the firstelectrically-conducive layer, and subsequently, part or all of the pixelelectrode is removed.

(18) The method according to (17), wherein

the pixel electrode is configured of a reflective electrode film and atransparent electrode film, and

the second electrically-conducive layer is formed by removing part orall of the transparent electrode from the pixel electrode.

(19) An electronic apparatus with a display unit, the display unitincluding:

a display layer including a pixel electrode;

a semiconductor layer provided in a layer below the display layer, thesemiconductor layer including a wiring layer that includes a materialremovable by an etchant by which the pixel electrode is also removable;and

a terminal section configured to electrically connect the semiconductorlayer to an external circuit, the terminal section including a firstelectrically-conductive layer made of a material same as a material ofthe wiring layer.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention is claimed as follows:
 1. A display unit comprising: adisplay layer including a pixel electrode; a semiconductor layerprovided in a layer below the display layer, the semiconductor layerincluding a wiring layer; and a terminal section configured toelectrically connect the semiconductor layer to an external circuit, theterminal section including a first electrically-conductive layer and aprotective layer, wherein the wiring layer and the firstelectrically-conductive layer each have a laminated structure includinga first Ti layer, an Al layer, and a second Ti layer in order, whereinthe pixel electrode has a configuration in which a first pixel electrodelayer including indium tin oxide (ITO) and a second pixel electrodelayer including aluminum (Al) or an aluminum alloy are laminated, thesecond pixel electrode layer contacting the wiring layer, and whereinthe protective layer, in a cross-sectional view, covers a part of a topsurface and side surfaces of the first electrically-conductive layerwithout covering top surfaces or side surfaces of the wiring layer. 2.The display unit according to claim 1, wherein the protective layercomprises SiN.
 3. The display unit according to claim 1, wherein theterminal section further includes an insulating film that covers top andside surfaces of the protective layer.
 4. The display unit according toclaim 3, wherein the insulating film further covers a portion of the topsurface of the first electrically-conductive layer.
 5. The display unitaccording to claim 1, wherein the second pixel electrode layer does notcontact the first electrically-conductive layer.